Appliance for use in ascertaining distances or altitudes.



6 0 9 1 5 1 Y A M D E m N E T A P R. H. OWEN.

APPLIANCE FOR USE IN ASGERTAINING DISTANCES OR ALTITUDBS'.

APPLICATION FILED AUG. 29, 1905.

Z 2 SHEETS-SHEET 1.

2 TO NK Wm WM H m E m R ms ATTERN ANDREW, a GRAHAM cov vnoro muosmwens. wasnmemm n. c

No. 820,597- PA'TENTED MAY 15, 1906.

. R. H. OWEN. APPLIANCE FOR USE IN ASOERTAINING DISTANCES 0R ALTITUDES. I

APPLIOATION FILED AUG. 29, 1905.

2 SHEETS-SHEET 2.

\AHY'NESSES, \NVENTQR,

M RQBERT HHYLQCKOWEN,

ANDREW u cw-mm an. PuOID-LITHOGRAPNERS. wAsnmcrou, ay 0.

UNITED STATES PATENT OFFICE.

ROBERT HAYLOCK OWEN, OF WELLINGTON, NEW ZEALAND. APPLIANCE FOR USE IN ASCERTAINING DISTANCES OR ALTITUDESL Specification of Letters Patent.

Patented May 15,;1906.

Application filed August 29,1905. Serial No. 276,228.

To all whom it may concern.-

Be it known that I, ROBERT IIAYLooK OWEN, a subject of the King of Great Britain, residing at Wellington, in the Colony of New Zealand, have invented a new and useful Appliance for Use in Ascertaining Distances or Altitudes, the same being particu larly applicable for use in range-finding; and I do hereby declare the following to be a full, clear, and exact description of the same.

This invention relates to improved appliances that have been designed for use in ascertaining distances and altitudes in a quick and eflicient manner.

The invention has been particularly devised for use in range-finding for rifle or artillery shooting whether on the sea or on the land and for use in topographical survey work.

The principle of calculation upon which the invention has been based consists in the fixed proportions that exist between the sides of triangles having the same angles. A basic triangle is obtained having a known base and the angles of which and the proportions of the sides to the base are known. A second triangle, one of the sides of which is the distance to be computed, is then obtained upon a measured base with angles similar to those of the basic triangle. The sides of such triangle will then bear the same proportion to the base as do those of the first or basic triangle.

The appliance devised has been designed in order to lndicate upon a graduated scale the direct ratio between the measured base of the triangle and the side whose length is the distance that is to be computed.

In describing the invention reference will be made to the accompanying sheets of drawings, in Which Figure 1 is a plan of the form of appliance adapted for use in ordinary range-finding or survey work. Fig. 2 is a side elevation, and Fig. 3 is an end elevation, of the same. Figs. 4c, 5, and 6 are sectional plan, underneath plan, and side elevation, respectively, of a form of appliance suitable fornaval purposes.

Referring first to the form of appliance shown in Figs. 1 to 3, a is a base-plate of metal of any desired length, the back end of which is turned up at right angles, as at b, and is provided with a sighting-aperture c, Fig. 3, therein in line with the center line of the base-plate. Upon the topface of the baseplate a at its fore end is pivoted an arm (1, that extends longitudinally along to near the other end of the base-plate. A pointed arm 6 is pivoted at this end of the base-plate, and it overlies the free end of the arm 11. The extremity of the arm (1 is connected to the pointer-arm e by means of a pin f, passing through a slot 9, formed in such arm. Thus as the arm (1 is moved to either side upon its pivot the pointer-arm e will be caused to turn upon its pivot to pass over graduated markings upon plates 7, hinged to the base-plate a one on each side of the arm at and adapted to be turned out or folded in on such base-plate, as shown in the drawing, Fig. 1. A screwpin j is mounted in a bearing k, secured upon one edge of the base-plate, and is threaded through a bearing secured to the arm (1. By revolving the screw in either direction the arm will be caused to move also in either direction, and thus operate the pointer-arm 6. This arrangement causes a greater proportional movement of the pointer when small angles are measured-i. e., a short base and a long distanceand a decreasing proportional movement of the pointer to that of the arm d when larger angles are measured, as would be the case in longer bases and shorter ranges. Pivoted upon the pivot-point of the arm (1 is a small frame Z, holding a narrow mirror min a vertical position. This frame and mirror are capable of being turned independently upon the pivot; but as the arm (1 is turned they will be turned with it. The mirror may thus be caused to assume any angle to the center line of the arm (1 that is desired. Pivoted to the same pivot, but beneath the baseplate, is a short plate n, the free end of which carries a mirror-frame 0, similar in construction to the frame Z and holding a mirror p in a vertical position. This frame is pivoted upon the plate so that it may be turned to assume any desired angle to the center line of the plate. Set-screws r are threaded upon the pivot-pins holding the mirror-frames Z and o and serve to lock such frames from movement in any position in which they may be placed. A spring-clip s is hinged to the bottom side of the plate a, by means of which the appliance may be clipped to a rifle-barrel or which when turned down to the position shown in the drawings will serve as a handle for holding it.

In the form of the appliance shown in Figs. 4 to 6, which represents a construction suit able for naval purposes, the base-plate a serves as the bottom of a casing 2, (shown in section in Figs. 4 and 6,)the rear end of which carries a telescope 3 in visual line with the center line of the base-plate. The rear end of the arm (1 is provided witha pin passing into a sliding block 5. A toothed sector 7 is pivoted upon the base-plate to the rear of the back end of the arm d, and this sector is formed with a slot 4:, into which passes the sliding block 5, which is kept in close contact.

with one side of the slot by means of the spring 6. A toothed pinion 8, which gears with the sector 7, is rigidly mounted upon a spindle 9, that passes vertically through bearings formed in the base-plate and casing and has secured to its bottom end an indicatorhand 10, which lies beneath a circular dial 11, secured upon the underneath face of the base-plate a. Turning movement is imparted to the arm (1 by means of the set-screw 12, passing through a threaded bearing 13 in the side of the casing. Such movement of the arm will cause a turning movement to the sector 7, which will cause the pinion8 to turn with its spindle and the hand 10 to travel round. the dial. The mirror m carried on the fore end of the arm d instead of being mounted in a swinging frame is rigidly fixed upon such arm at an angle of approximately forty-five degrees to its center line. An arm 14 is pivoted to the base-plate upon one side of the arm (1 and extends across to the other side thereof, where it is provided with a pin and set-screw 15, passing through a curved slot 16 in the base-plate to allow of the arm being turned on its pivot and locked at any desired point. This arm also carries the second mirror p on its pivot end and fixed so as to lie longitudinally in a line with the center line of the arm. This arm is made capable of sufficient turning movement to allow of the two mirrors m and p, when the arm (1 is in a line coincident with the center line of the baseplate, being placed either parallel or at an angle of forty-five degrees to each other.

In using the appliances for ordinary rangefinding the arm d is first placed in the central position shown in the drawings. The mirrors m and p are turned so that their faces shall assume an angle of forty-five degrees to each other. Sight is then taken through the sighting-hole or telescope, according to which instrument is being used, until the distant range-point becomes reflected upon the center of the mirror m. The range-finder will thus be facing at right angles to the rangepoint. Sight is then taken over the top of the mirror of some distant fixed object in a line with the reflection of the range-point, and the operator moves toward or away from such distant object any convenient distance in a straight line with the position in which sight was first takensay for fifty yards. Still keeping the appliance in a line with the direction of his movement, which is at right angles to a line between the first sightingpoint and the range-point, sight is again taken and the mirror m moved by actuating the arm cl until the reflection of the rangepoint is thrown again by the mirror 19 into a line with the distant object. This movement of the arm d will cause the pointer-arm e or hand 10 to pass over the graduated markings upon one of the plates h or dial 11. These markings have been made to accord with a direct ratio between the measured base and the side of the triangle whose length is to be computed. Thus when the mirror m has been adjusted at the second sighting-point to reflect the range-point the indicator-arm will be in coincidence with a marking upon the scalesay 20. The range will then be obtained by a multiplication of the base traversed by the scale-number, or 50 X 20 1,000. In obtaining this result a triangle is constructed the base of which and the two angles at the base are known. The appliance is also serviceable in ascertaining the distance between any two objects at a distance or in calculating the altitudes of hills or prominences. The former of these operations is carried out by first ascertaining the distance of the objects from the sighting-point in the manner before describedsay two thousand yards. The mirror 1) is then turned so that it shall be parallel with the mirror m. To adjust the mirrors in a perfectly parallel state, the arm d is moved until the reflected view of one of the objects coincides with the direct view thereof when sight is taken along the appliance. After such has been done the arm d is moved so as to cause the mirror m to turn until the reflected image of one of the distant objects is coincident with the direct view of the other object. The indicator-pointer will by this movement of the arm d have been I caused to travel over the scale-markings. The number with which such pointer coincidessay 20,will then be the inverse ratio of the distance between the two objects to the distance away from the sighting-point. The actual distance is thus 2,000 20, or one hundred yards.

For ascertaining altitudes the appliance is held on its side and the bottom of the hill is made to coincide with the reflection of the top thereof, or vice versa. When the distance away from each other of any two fixed objects has been thus obtained, the range at any distance therefrom may be found by causing the reflection of one object to coincide with the actual sight of the other and multiplying the distance between the objects by the number on the scale to which the indicator points. Thus the instrument will be found of great value for use in army attacks in which the forces move up from a point without the range distance into the range, the distance away at any intermediate point being thus found without the necessity of the range-finder having to traverse a base.

Other ways of constructing the appliances I may be devised without departing from the spirit of this invention, and I do not wish to confine myself exclusively to those shown in the accompanying drawings and described herein; but

What I do claim as my invention, and desire to secure by Letters Patent, is-

1. In appliances for use in ascertaining distances and altitudes, a base-plate, a pair of mirrors mounted in a vertical position thereon and the reflecting-surfaces of which are adjustable in regard to the horizontal angle between them, an arm pivoted upon the baseplate and extending longitudinally along its top face and adapted to turn one of the mirrors in a horizontal plane when it is moved, a pointer operated by the free end of the pivoted arm, a plate bearing scale-markings of a direct ratio between a measured base and the distance to be computed, over which the pointer passes, an a sight at one end of the base-plate in a line with the center line thereof, substantially as herein specified.

2. In ap liances for use in ascertaining distances or a titudes, a base-plate the back end of which is rovided with a sight in a line with the center ine thereof, a pointer carried by said base-plate, plates bearing scale-markings over which said pointer passes, a mirror pivotally held in a vertical position, a second mirror also pivotally held in vertical position,

and means whereby the reflecting-surfaces of the two mirrors may be made parallel 'or caused to assume any desired angle to each other, and which operate also to move the pointer over said scale-markings, substantially as herein specified.

3. In ap liances for use in ascertaining distances or a titudes, a base-plate the back end of which is provided with a sight, an arm pivoted on the top face of the base-plate at its fore end and extending to its back end, means whereby such arm may be moved in either direction, a mirror supported in a vertical position upon the fore end of the arm and capable of being adjusted to any angle with regard to the center line thereof, a plate piv oted to the fore end of the baselate, a second mirror carried upon such p ate and capable of being adjusted to any angle with regard thereto, a pointer connected to the free end of the pivoted arm and adapted to be operated thereby, and an a pliance bearing scale-markings over which the pointer passes, substantially as herein specified.

In testimony whereof I have signed this specification in the presence of two subscribing Witnesses.

ROBERT HAYLOOK OWEN.

Witnesses W. ALEXANDER, W. M. BooLAsE, 

